中国西南地区鹿药属4种15居群核型研究

对产于中国西南部的鹿药属（Maianthemum）4种植物进行了细胞学研究，包括染色体数目，多倍化，非整倍性和随体染色体，以及核型不对称性和核型进化。结果表明：1）除了在云南丽江采集的Maianthemum tatsienensis染色体数目为2n=72之外，其余的居群全为2n=36；2）核型在居群间存在变异，特别是在具中部染色体和近中部染色体的数目以及随体染色体的数目和位置上。此外，M．nanchuanense和M．szechuanicum的核型是首次报道，B染色体也是首次在该属中发现。我们推测鹿药属的进化方式包括频繁的染色体畸变以及不同水平上的多倍化，而中国西南部是该属的分化中心。

Karyotypes of Fifteen Populations of Four Species in Maianthemum (Liliaceae) from Southwestern China

Fifteen populations of four species of Maianthemum from southwestern China were analyzed in terms of base number, polyploidy, dysploidy, chromosome size, chromosome morphology, satellited chromosomes, structural heteromorphism, and karyotype asymmetry and karyotype evolution. The results show that 1) chromosomal number of all the species examined is 2n=36, with M tatsienensis (Population Lijiang, Yunnan) as an exceptional case of which the chromosomal number is 2n=72; 2) karyotypes show difference among populations, especially in the numbers of metacentric, submetacentric, and acrocentric chromosomes as well as satellites. The karyotypes of M nanchuanense and M szechuanicum are documented the first time. B-chromosome is discovered in this genus the first time, too. It is inferred that the evolutionary mechanisms in the genus Maianthemum include the frequent somatic chromosome aberration and the polyploidy at various levels, and that the southwestern China is one of the differentiation centers of this genus.